Making a mini-greenhouse

[stealthwolf]

I was thinking about making one of these:

https://www.greenfingers.com/product.asp?dept_id=500546&pf_id=LS6536D

but to a custom size (I need it taller and deeper). I don't have enough space for a proper greenhouse. I don't need the middle shelves.

What could I use for "glass"? I was thinking of this: http://www.wickes.co.uk/Wickes-4mm-Twinwall-Polycarbonate-Sheet-610X1220mm-Pack-10/p/118772

How would I attach the polycarbonate sheet to the wood frame? Screw? Epoxy?

In the absence of shelves, would I need extra bracing? I was thinking about adding a few cross-members at the same height of the shelves.

Any other thoughts or suggestions would be welcome.

 

[Burnerman]

Polycarbonate sheet is what you need here......single thickness stuff is stronger, the twin wall stuff weaker but maybe warmer. You can attach the sheet using brass or stainless screws or silicone sealant - maybe both, but not epoxy resin glues.
To stiffen things up, fix a diagonal brace at the back and also the sides.
Are there aluminium alternatives available? Thinking of the wood rotting etc.
John

 

[stealthwolf]

Are there aluminium alternatives available? Thinking of the wood rotting etc.

Thanks for the reply. I don't mind rebuilding it if needed a few years down the line. We bought a metal framed one: clicky but it is so woefully inadequate and flimsy that I realised it'd be better to get a "proper" one but the dimensions I need are tricky (W1000, D500, H1200-1500).

It's mainly to grow tomatoes and maybe a few smaller plants whilst keeping out slugs and other pests.

I've already sawed some scaffold boards to make some raised beds.

 

[Burnerman]

Maybe you could make your frames without a bottom rebate, so rain would drain off, rather than soaking the timber? Just a thought - I've seen so many cold frames made from old windows that are totally knackered after a year or two.
John

 

[stealthwolf]

I could raise the base to minimize it. Otherwise was thinking of some sort of lacquer or decking finish to protect the wood to some degree. The top would be sloped to allow run off.

 

[Burnerman]

If you give the sloped top a good overhang, it could minimise damage to the lower panes as rain water would drip clear. The original design seems to have a hinged top so it shouldn't be too much of a problem.
John